Human memory is often viewed as comprising both short term memory and long term memory. Short term memory refers to that which an individual can recall within a few seconds to a few minutes of being exposed to a given experience. This kind of memory tends to degrade quickly. Long term memory, on the other hand, refers to that which an individual can recall for a much longer period of time following the aforementioned exposure; this can be hours, days, or years.
These are not merely semantically-based categorizations. Short-term memory is presently viewed as being supported by transient patterns of neuronal communication that are dependent on regions of the frontal lobe (and in particular the dorsolateral prefrontal cortex) and the parietal lobe. Long-term memories, on the other hand, are presently viewed as being maintained by more stable and permanent changes in neural connections that are widely spread throughout the human brain.
The ability to develop new long term memories can become impaired for any number of reasons. Various illnesses can have this effect as can other physical impairments of various kinds. Similar impairment can occur with individuals who experience considerable cognitive loading, emotional distress, and so forth. In some cases the problem can be relatively fully developed almost immediately and in other cases can develop gradually over an extended period of time. In any event, an inability to reliably develop new long term memories can be highly problematic for a given individual as well as those with whom that individual interacts.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.